In developing animal models for understanding affective disorders of the face, including emotional expression deficits, various modes of facial paralysis, and specific speech disorders, researchers must describe the motor-component of the deficit. To date there is no methodology for quantifying these movement deficits in a monkey, not to mention a means with which these deficits may be compared to those that characterize neurological conditions in humans, such as Parkinson's disease, autism, depression or other affective disorders. Such a procedure, however, is critical, not only for documenting the severity of the deficit, but for quantifying resulting improvements after treatment. This project will develop a rigorous, objective and standardized tool for quantifying facial movement in the rhesus monkey, the species used most widely as a model for human biobehavioral, neurobiological, and affective disorders. This measurement tool is based directly on the human Facial Action Coding System (FACS), which is an anatomically-based system for quantifying facial movement according to the action of the underlying musculature. Therefore, we propose three specific aims to meet these goals. First, we will validate the location and organization of the facial musculature of the rhesus monkey using modern dissection techniques. Second, we will objectively qualify the facial appearance changes produced by stimulating each facial muscle in anesthetized monkeys using intramuscular electrical stimulation and then documenting the resulting facial movements. Third, once these basic components have been documented, we will establish a numerical system, using FACS criteria and terminology, to describe each individual component movement, i.e. a movement map, for the rhesus face. Finally, we will use existing video recordings of spontaneous behavior in rhesus to qualify the degree of intensity that is typical for each movement. These results will be packaged into a manual form, complete with photographic documentation of each movement at its varying levels of intensity for distribution to researchers in related areas of neuroscience and public health who work with animal models for clinical disorders. Not only with this system (MaqFACS) provide seminal data on the expressive facial repertoire of the rhesus monkey, benefiting those interested in natural ethology and communication, it will provide the standardization necessary for describing facial movement deficits, quantifying their degree of severity and range of improvement, in studies where monkeys are used as models for human affective and related disorders. Researchers using monkeys to model aspects of human affective and related disorders, including Parkinson's disease and depression, currently have no standardized method for quantifying deficits in facial movement, although such deficits are prominent in the phenotypes of many human disorders. This project aims to develop an anatomically- based system for measuring facial movement in the rhesus monkey, the main primate model for human affective disorders that is objective, standardized, and directly comparable to methods used for quantifying human facial movement in clinical studies (Ekman, Friesen &Hagar, 2002). The development of this system is critical for researchers to quantify the severity of facial movement deficits and evaluate improvements after clinical treatment. Ultimately, this system will advance our ability to model and treat human affective diseases.